Coke ovens have a structure wherein a carbonizing chamber and a combustion chamber are alternately arranged in the direction of coke oven battery. From a coal charging car which travels on the top of the coke oven in the direction of coke oven battery, coal is charged into each of the carbonizing chambers, and heat from each of the combustion chambers is transferred to the carbonizing chambers. In such a way, the charged coal is subjected to dry distillation, so as to produce coke.
Many of the coke ovens of this type have gone through over thirty years since they were built. Thus, the coke ovens have become decrepit. About firebricks which constitute side walls of the carbonizing chambers, which will be referred to as oven walls hereinafter, a cycle is repeated wherein carbon adhering to damaged regions of the oven walls is peeled by push-out of coke or charge of coal so that the oven walls are further damaged. As a result, factors of hindering the oven operation, such as a deformation of the oven walls, have been standing out.
Under such a situation, grasping the state of oven walls has become a very important inspection item for keeping a stable oven operation.
In carbonizing chambers in a coke oven, oven walls are opposed to each other with a narrow width. When the oven walls are damaged or worn away, the distance between the two wall surfaces becomes large. Thus, when the oven width is measured, the state that the oven walls are damaged or worn away can be guessed.
Thus, as an instrument for measuring the oven width, disclosed is a structure wherein a pair of noncontact distance meters which can be directed to individual oven walls of carbonizing chambers is mounted to a ram beam of a coke pushing-out machine in, for example, Japanese Unexamined Patent Publication No. 62-293112.
In this oven width measuring instrument, a water cooling jacket receives therein the noncontact distance meters in such a manner that measurement can be performed in the carbonizing chambers, the temperature of which may rise up to 1000° C. or higher. According to this structure, it is essential to lay a cooling pipe for supplying cooling water to the water cooling jacket and returning heatup water used for cooling from the water cooling jacket. Thus, it is inevitable that the cooling device attached to the oven width measuring instrument is made large-sized.
Furthermore, the distance over which the cooling water can be supplied is restricted by the pump discharging performance, and others, there is an inconvenience that the oven width cannot be continuously measured while the distance meter moves to the individual carbonizing chambers.
As an oven width measuring instrument without a cooling pipe, for example, Japanese Unexamined Patent Publication No. 2002-213922 discloses an oven width measuring instrument having a structure wherein an oven width distance meter and a power supply device are accommodated in a heat absorbing box and measured data of the oven width are transmitted through a transmitting device set in the heat absorbing box wirelessly.
The heat absorbing box is made of a jacket filled with liquid, and the outside of the heat absorbing box is covered with a heat insulating material. According to such an oven width measuring instrument, the measurement area is not restricted since no cooling pipe is required.
However, according to the oven width measuring instrument described in the Japanese Unexamined Patent Publication No. 2002-213922, the continuation of the measurement becomes unable at the time when the temperature of the liquid inside the water cooling jacket reaches the service temperature limit of the oven width measuring instrument. Thus, the measurement undergoes time restriction.